An ink jet head includes a flow path formation member in which a plurality of ink chambers are formed, a nozzle plate on which a plurality of nozzles that communicate with the respective ink chambers are formed, and a head substrate on which a plurality of elements, such as actuators, corresponding to the ink chambers are arranged.
The head substrate may be connected to a printer control unit via a flexible substrate, a relay substrate, a cable, or the like. A drive integrated circuit (IC) chip that drives the plurality of elements may be mounted on the flexible substrate in some cases.
The drive IC chip outputs drive power in accordance with a command from the printer control unit and supplies the drive power to the respective elements. In this manner, the elements are deformed or caused to generate heat and thus an ink pressure in a pressure chamber increases, and ink is ejected from the nozzles.
Discrete wirings for supplying drive signals and a common wiring for supplying a reference potential (ground potential) may be connected to the respective elements.
The common wiring may be disposed through a different route without the flexible substrate interposed therebetween or is disposed via the drive IC chip on the flexible substrate.
If the common wiring is disposed through a route that is different from the flexible substrate, the wiring may become long and complicated. This may increase noise or lead to degradation of ejection properties due to voltage dropping. Also, a wiring connecting operation may become cumbersome.
If the common wiring is disposed via the drive IC chip on the flexible substrate, improper operations of the drive IC may occur due to noise that is transmitted through the common wiring. Also, the common wiring may need to be formed with a thin width, and this may lead to degradation of ejection properties due to voltage dropping. If the width of the common wiring is increased, an area of the drive IC may increase.